Temperature dependence on the electrical and physical performance of InAs/AlSb heterojunction and high electron mobility transistors

In this report, the effect of temperature on the InAs/AlSb heterojunction and high-electron-mobility transistors (HEMTs) with a gate length of 2 μ are discussed comprehensively. The results indicate that device performance is greatly improved at cryogenic temperatures. It is also observed that the device performance at 90 K is significantly improved with 27% lower gate leakage current, 12% higher maximum drain current, and 22.5% higher peak transconductance compared to 300 K. The temperature dependence of mobility and the two-dimensional electron gas concentration in the InAs/AlSb heterojunction for the temperature range 90 K-300 K is also investigated. The electron mobility at 90 K (42560 cm²/V·s) is 2.5 times higher than its value at 300 K (16911 cm²/V·s) because of the weaker lattice vibration and the impurity ionization at cryogenic temperatures, which corresponds to a reduced scattering rate and higher mobility. We also noted that the two-dimensional electron gas concentration decreases slightly from 1.99×10¹² cm^-2 at 300 K to 1.7×10¹² cm^-2 at 90 K with a decrease in temperature due to the lower ionization at cryogenic temperature and the nearly constant ΔE_c.